ELECTRODE COMPOSITION FOR A SECONDARY BATTERY CELL

• US 20140335410A1
• Filed: 10/26/2012
• Published: 11/13/2014
• Est. Priority Date: 05/11/2009
• Status: Active Grant

• Current Assignee: SK On Company Limited (SK Innovation Company Limited)
• Original Assignee: Nexeon Limited
• Inventors: Loveridge, Melanie J., Lain, Michael Jonathan, Coowar, Fazil, Abdelsalam, Mamdouh Elsayad
• Granted Patent: US 9,853,292 B2
• Time in Patent Office: Days
• US Class Current: 429/217
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 4/13 Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• CPC Class Codes: H01M 4/362 Composites
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: H01M 4/622 being polymers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Disclosed are a composite electrode material for a rechargeable battery; a method of making a composite electrode material; an electrode including the composite electrode material; cells including such electrodes; and devices including the cells. A composite electrode material for a rechargeable battery cell includes an electroactive material; and a polymeric binder including pendant carboxyl groups. The electroactive material includes one or more components selected from the group including an electroactive metal, an electroactive semi-metal, an electroactive ceramic material, an electroactive metalloid, an electroactive semi-conductor, an electroactive alloy of a metal, an electroactive alloy of a semi-metal and an electroactive compound of a metal or a semi-metal. The polymeric binder has a molecular weight in the range 300,000 to 3,000,000. 40 to 90% of the carboxyl groups of the binder are in the form of a metal ion carboxylate salt.

Claims

1. A composite electrode material for a rechargeable battery cell, comprising:

a. an electroactive material comprising at least one of A) an electroactive element, wherein the electroactive element is selected from the group comprising silicon, tin, gallium, germanium, aluminium, zinc, bismuth, antimony, indium and mixtures thereof, or a ceramic titanate, B) an alloy of an electroactive element with a non-electroactive metal, or C) an electroactive compound containing an electroactive element; and

b. a polymeric binder comprising carboxyl groups, the binder comprising a polymer of one or more monomers selected from the group;

acrylic acid, 3-butenoic acid, 2-methacrylic acid, 2-pentenoic acid, 2,3-dimethylacrylic acid, 3,3-dimethylacrylic acid, itaconic acid and fumaric acid;

characterized in that

i) the polymeric binder has a number average molecular weight in the range 300,000 to 3,000,000;

ii) 40 to 90% of the carboxyl groups of the polymeric binder are in the form of a metal ion carboxylate salt; and

iii) the metal ion of the metal ion carboxylate salt is selected from sodium, potassium, calcium, magnesium, caesium and zinc.

2-80. -80. (canceled)

81. A composite electrode material according to claim 1, in which 60 to 80% of the carboxyl groups are in the form of a metal ion carboxylate salt.

82. A composite electrode material according to claim 1 which further comprises an electroactive carbon selected from graphite, hard carbon, carbon microbeads and graphene, wherein the electroactive carbon constitutes 0 to 70 percent by weight of the total weight of the electroactive materials of the composite electrode material.

83. A composite electrode material according to claim 82, wherein the electroactive material and the electroactive carbon together constitute at least 50 percent by weight of the composite electrode material.

84. A composite electrode material according to claim 1, which comprises 0.5 to 15 percent by weight of the polymeric binder.

85. A composite electrode material according to claim 1, which further comprises 4 to 16 percent by weight of a conductive carbon selected from one or more of carbon black, acetylene black, ketjen black, lamp black, carbon nano-tubes and vapour grown carbon fibres.

86. A composite electrode material according to claim 1, wherein the electroactive material is a structured electroactive material selected from one or more of the structure group comprising particles, elongate elements, pillared particles, porous particles, porous particle fragments, substrate particles, bundles of elongate elements, and scaffold structures.

87. A composite electrode material according to claim 1, wherein the electroactive material comprises an elongate element selected from the group comprising fibres, threads, pillars, wires, nano-wires, filaments, tubes, ribbons and flakes.

88. A composite electrode material according to claim 87, wherein the fibre, thread, pillar, filament or wire has an aspect ratio in the range of 5:

1 to 1000;

1.

89. A composite electrode material according to claim 1, wherein the electroactive material comprises particles having a diameter in the range 1 μ

m to 20 μ

m.

90. A composite electrode material according to claim 1, wherein the electroactive material is selected from a ribbon, a flake and a tube having a first dimension in the range of 0.03 μ

m to 2 μ

m.

91. A composite electrode material according to claim 1, wherein the electroactive material comprises a pillared particle having an overall diameter in the range 5 to 30 μ

m and/or a porous particle having a plurality of voids or channels extending therethrough having a maximum diameter of 1 to 40 μ

m.

92. An electrode for a rechargeable battery comprising a current collector and a composite electrode material according to claim 1.

93. An electrode according to claim 92, wherein the composite electrode material is in the form of a layer adhered to the current collector, said composite electrode material having a thickness of at least 6 μ

m and no more than 60 μ

m.

94. An electrode according to claim 92, wherein the composite electrode material has a porosity of at least 10% and no more than 60% in the uncharged state.

95. A cell comprising an electrode according to claim 92 comprising a composite electrode material, a cathode, a separator and an electrolyte.

96. A cell according to claim 95, wherein the composite electrode material of the electrode forms a gel on contact with the electrolyte.

97. A device comprising a cell according to claim 95.

98. A composite electrode material according to claim 1, wherein the electroactive material is a silicon oxide (SiO_x) where 0≦

x≦

2.